The present invention concerns cooling systems for internal combustion engines, particularly for motor vehicles.
More specifically, the object of the invention is a cooling system for an internal combustion engine comprising a hydraulic circuit for supplying coolant to the engine, including
a circulation pump, PA1 a radiator connected to the engine, PA1 a by-pass duct essentially parallel with the radiator, and PA1 a regulating valve capable of adjusting the ratio of the flows of coolant supplied to the engine through the by-pass duct and radiator respectively. PA1 the output of the circulation pump varies as a function of a control signal; PA1 a sensor is provided capable of providing signals indicating the temperature of the liquid flowing through a predetermined zone of the engine or the said hydraulic circuit; PA1 an electronic unit for controlling the pump is connected to the sensor such that the output of the pump varies in a predetermined manner depending on the temperature detected by the sensor; and PA1 the regulating valve adjusts the ratio between the aforesaid flows of coolant as the output of the said pump varies.
In cooling systems of this kind produced until now, the circulation pump is a mechanical pump, in practice incorporated in the internal combustion engine and rotated thereby. The regulating valve in these systems is a thermostatic valve.
These known systems are structurally complex and expensive and, although they operate satisfactorily, they enable only a relatively inflexible control of the engine temperature.